first stab at restoring the ~/.chefdk dir for installing user gems, but ...

[tknerr]

...it still fails the acceptance tests

Note: Keeping this PR open until the underlying issues are fixed.

Essentially I want to restore the default behaviour of ChefDK where gems are installed into ~/.chefdk rather than the chefdk embedded dir. This would be a clean separation between the chefdk shipped gems and the user / bundle installed gems again. It works on my ubuntu dev-box without problems that way, but in bills kitchen it still fails the acceptance tests:

"--> Running command: 'cd C:/Repos/_github/bills-kitchen/target/build/repo/vagrant-workflow-tests/playground/sample-toplevel-cookbook && rake test':"
knife cookbook test sample-toplevel-cookbook -o ..
'"C:\Repos\_github\bills-kitchen\target\build\home\.chefdk\gem\ruby\2.0.0\bin\ruby.exe"' is not recognized as an internal or external command,
operable program or batch file.
rake aborted!

Might have to do or is related to the chefdk mangling we do here:
https://github.com/tknerr/bills-kitchen/blob/master/Rakefile#L117-132

Related ChefDK issues:

• Wrong path for ruby.exe for ChefDK 0.3.5 on Windows for Several Commands chef-boneyard/chef-dk#242
• Chef should be installable to a different directory on Windows. chef/chef#1512

[tknerr]

As mentioned here, the upstream fix in RubyGems 2.4.4 should resolve the ruby path issues.

So it will likely be fixed with the next ChefDK and we could probably get rid of lots of the cruft in here:
https://github.com/tknerr/bills-kitchen/blob/master/Rakefile#L117-132

[tknerr]

fixed via #72 (original commits here cherry-picked)